1. Field of the Invention
The present invention relates to a magnetic tape device, and more particularly to a magnetic tape device in which the reference position of a tape cassette is restricted by pressing the tape cassette against seats.
2. Description of the Related Art
FIGS. 12 to 17 illustratively show main portions of a magnetic tape device of this kind. The magnetic tape device includes seats 21, 22, and 23 which are shown in FIG. 16 or 17, and which are defined in the same level, at plural places of a metal chassis 10 having lateral side plates 11. Among the seats, the two illustrated seats 21 and 23 are formed by the upper end faces of raised pieces 13 and 14 which are formed by raising portions of the chassis 10, respectively, and the other seat 22 is formed by the upper end face of a column 15 which is made of a synthetic resin, and which is attached to the chassis 10. The two seats 21 and 22, which are laterally aligned, are provided with guide pins 24 and 25 having tapered top end, respectively.
As shown in FIG. 12, a cassette table 30 is attached between the lateral side plates 11 of the chassis 10. The cassette table 30 includes a support plate 31 which is configured by a laterally extending metal plate member, lateral side walls 32 which are fixed to lateral ends of the support plate 31 respectively, and cassette pressers 33 which are disposed integrally with upper end portions of the side walls 32 respectively. As shown in FIGS. 14 and 15, a spring plate 34 is attached to one of the cassette pressers 33, and a stopper 37 is disposed on one of the side walls 32. The other cassette presser 33 and the other side wall 32 are configured in the same manner as described above. As shown in FIG. 12, a projection 35 and a guide pin 36 are outwardly projected from each of the lateral side walls 32. The projections 35 and the guide pins 36 are slidably fitted into cam grooves 16 and 17 which are symmetrically formed in the lateral side walls 32, and which are indicated by the phantom lines in FIG. 13, respectively. A reciprocation path A1 which longitudinally elongates, and a lift path A2 which vertically elongates are formed by each of the cam grooves 16 into which the projections 35 are fitted. The cam grooves 17 into which the guide pins 36 are fitted are configured in the same manner.
As shown in FIG. 12, table driving levers 40 are placed inside the lateral side plates 11, respectively. The swinging operations of the table driving levers 40 are synchronized with each other by a synchronization shaft 41, and the table driving levers can be swung about the axis P which is indicated by the dashed line in FIG. 12. As can be seen also from FIG. 13 showing one of the table driving levers 40, the basal portion of the table driving lever 40 is attached to the lateral side plate 11 of the chassis 10 via a support shaft 42. The axis of the support shaft 42 is brought into line with the above-mentioned axis P. A groove 43 into which the projection 35 is fitted is formed in the table driving lever 40. A spring member 44 configured by a torsion coil spring which presses the projection 35 against a groove wall 43a of the groove 43 is attached to the table driving lever. The table driving lever 40 is swung in longitudinal and vertical directions about the axis P by a driving source which is not shown.
In the thus configured conventional magnetic tape device, the cassette table 30 is moved in a cassette traveling path which elongates between a cassette insertion position and a cassette delivery position which is below the cassette insertion position. As shown in FIG. 13, the cassette traveling path A is formed by the reciprocation path A1 and the lift path A2.
When the cassette table 30 is located at the cassette insertion position, the projections 35 are located in the reciprocation paths A1 as indicated by the solid line in FIG. 13. A box-like tape cassette 100 is inserted on the cassette table 30 which is waiting at the cassette insertion position. After the tape cassette 100 is inserted on the cassette table 30, as shown in FIG. 14, the tape cassette 100 is placed on the support plate 31 and abuts against the stoppers 37, and is elastically pressed against the support plate 31 by the spring force of the spring plate 34. Therefore, the tape cassette 100 is positioned to a predetermined position of the cassette table 30.
When the table driving levers 40 are backwardly swung from this state as indicated by the arrow R in FIG. 13, the projections 35 which are pressed against the groove walls 43a by the spring members 44 are backwardly moved in the reciprocation paths A1 in accordance with the backward swinging of the table driving levers 40. Thereafter, the table driving levers 40 are downwardly swung, so that the projections 35 which are pressed against the groove walls 43a by the spring members 44 enter the lift paths A2 from the reciprocation paths A1 and then go down in the lift paths A2. Therefore, the cassette table 30 is moved together with the projections 35 along the reciprocation paths A1 and the lift paths A2. When the projections 35 are pressed down in the lift paths A2 by such an operation of the table driving levers 40, the cassette table 30 also is lowered together with the projections 35. On the way of the lowering of the cassette table 30, as shown in FIG. 17, positioning holes 110 formed in the tape cassette 100 placed on the support plate 31 are fitted onto the guide pins 24 and 25 respectively, and the tape cassette 100 sits on the seats 21 and 22, and also on the seat 23 shown in FIG. 16.
After the tape cassette 100 sits on the seats 21, 22, and 23, the table driving levers 40 are slightly downwardly swung. By the swinging of the table driving levers 40 in this stage, the cassette table 30 is lowered in accordance with the pressing down operation of the projections 35, and the cassette pressers 33 abut against the upper face of the tape cassette 100 as shown in FIG. 15. After the cassette pressers 33 abut against the upper face of the tape cassette 100 in this way, the spring members 44 which are engaged with the projections 35 are deformed against their elasticity, whereby the table driving levers 40 are allowed to swing (the arrow R1) until the levers reach their limit positions. In a state where the table driving levers 40 are fully swung to the limit positions, the cassette pressers 33 downwardly press the tape cassette 100 against the seats 21, 22, and 23 (see FIGS. 16 and 17) by a force corresponding to the reaction force to the elastic deformation of the spring members 44 as indicated by the arrow d in FIG. 15. In this way, the tape cassette 100 is positioned to a reference position for tape loading, recording and reproduction, and the like.
JP-A-10-162459 (prior art example 1) discloses a magnetic tape device which is configured in a substantially similar manner as the above-described conventional magnetic tape device. JP-A-2-58755 (prior art example 2) discloses a cassette loading device including a spring plate which is of the same kind as the spring plate 34 used in the above-described conventional magnetic tape device.
In the conventional magnetic tape device described above, the spring plate 34 for positioning the tape cassette 100 with respect to the cassette table 30, and the spring members 44 for pressing the tape cassette 100 sitting on the seats 21, 22, and 23 against the seats 21, 22, and 23 to position the cassette to the reference position are required. Moreover, steps of attaching these components are necessary. Therefore, there arises a problem in that the numbers of parts and assembly steps are correspondingly increased, so that the production cost is raised.
The above mentioned prior art example 1 shows members corresponding to the spring members 44, and prior art example 2 shows a member corresponding to the spring plate 34. Consequently, the problem cannot be solved by these prior art examples.
The invention has been conducted in view of the above circumstances.
In the invention, the attention is paid to the fact that a support plate disposed in a cassette table is formed by a metal plate member and the support plate has elasticity peculiar to a metal plate. It is an object of the invention to provide a magnetic tape device in which the spring members 44 that are employed in the conventional magnetic tape device can be omitted by using the above-mentioned elasticity of the support plate.
It is another object of the invention to provide a magnetic tape device in which the spring plate 34 that is employed in the conventional magnetic tape device can be omitted by using the above-mentioned elasticity of the support plate.
In order to solve the above problem, there is provided a magnetic tape device having a cassette table which is moved in a cassette traveling path that elongates between a cassette insertion position and a cassette delivery position which is below the cassette insertion position, the cassette table including a support plate on which a tape cassette is placed; a cassette presser disposed on the support plate, the cassette presser faces the tape cassette from an upper side; a table pressing-down member for lowering the cassette table from a position which is above the cassette derivery position toward the cassette delivery position; and a seat on which the tape cassette is sittable on the way of the cassette table down to the cassette delivery position, wherein the tape cassette is pressed down and positioned to a reference position by the cassette presser which moves together with the cassette table, the support plate is configured by an elastic plate member, swinging operation of the table pressing-down member in a state where the tape cassette sits on the seat is allowed by a sliding operation of the cassette pressers with respect to the tape cassette, the sliding operation being conducted with flexurally deforming the support plate against elasticity of the support plate.
According to this configuration, when the cassette pressers downwardly press the tape cassette sitting on the seats, the support plate is flexurally deformed against its elasticity by the sliding operation of the cassette pressers with respect to the tape cassette. Therefore, the cassette pressers press the tape cassette against the seats by a force corresponding to the reaction force to the elastic deformation of the support plate, thereby positioning the tape cassette to the reference position. Consequently, the support plate formed by the plate member having elasticity performs the same function as the spring members 44 which have been described with reference to FIG. 13, and hence the spring members 44 can be omitted.
In the invention, it is possible to employ a configuration in which the cassette pressers are continuously integrated with upper end portions of lateral side walls which are fixed to ends of the support plate, respectively, and which are opposed to side faces of the tape cassette placed on the support plate, respectively. According to this configuration, the cassette pressers can be configured in the same manner as those in the conventional art.
In the invention, it is possible to employ a configuration in which the table pressing-down member is configured by swing levers which are engaged with projections disposed on the side walls, respectively, and which is downwardly swung with using a given position as a fulcrum, thereby pressing down the projections to lower the cassette table from the position above the cassette delivery position toward the cassette delivery position. According to this configuration, the table pressing-down means can be configured without largely changing the configuration of the conventional art.
In the invention, it is possible to employ a configuration in which the side walls including the cassette pressers are fixed to lateral ends of the support plate, respectively, and the swing levers which operate in synchronization with each other are engaged with the projections disposed on the side walls, respectively. According to this configuration, the cassette table can be configured without largely changing the configuration of the conventional art.
In the invention, it is possible to employ a configuration in which each of the cassette pressers has a protruding piece which extends above the tape cassette placed on the support plate and a long an upper face of the tape cassette, and a protrusion which downwardly protrudes from the protruding piece to face the upper face of the tape cassette. Alternatively, a configuration in which each of the cassette pressers has a forward and upward inclined face which faces an edge of the tape cassette placed on the support plate may be employed. According to these configurations, the cassette pressers can be molded integrally with the side walls of the cassette table by a synthetic resin. This is useful for suppressing the number of parts to enable the cost reduction.
In the invention, it is preferable to configure the device so that the tape cassette which is placed on the support plate at the cassette insertion position is positioned with respect to the cassette table by clamping the tape cassette between the support plate and the cassette pressers. According to this configuration, the cassette pressers perform the same function as the spring plate 34 in the conventional art which has been described with reference to FIG. 14, and hence the spring plate 34 can be omitted.
The magnetic tape device of the invention can be configured in the following manner: a magnetic tape device having a cassette table which is moved in a cassette traveling path that elongates between a cassette insertion position and a cassette delivery position which is below the cassette insertion position, the cassette table including a support plate on which a tape cassette is placed, the support plate is configured by an elastic metal plate member; a plurality of side walls fixed to lateral ends of the support plate respectively, each of side walls having a projection; a plurality of cassette pressers disposed on upper end portions of the side walls, the cassette pressers face the tape cassette from an upper side; a plurality of swing levers engaged with the projection, the swing levers are downwardly swingable from a predetermined position thereby pressing down the projection to lower the cassette table from a position which is above the cassette delivery position toward the cassette delivery position; and a plurality of seats on which the tape cassette is sittable on the way of the cassette table down to the cassette delivery position, wherein the swing levers are configured respectively by members which are also used as table driving levers that move the cassette table between the cassette insertion position and the cassette delivery position through the cassette traveling path, the tape cassette placed on the support plate at the cassette insertion position is positioned with respect to the cassette table by being clamped between the support plate and the cassette pressers, the swinging operation of the swing levers for pressing down the projections in a state where the tape cassette sits on the seats is allowed by a sliding operation of the cassette pressers with respect to the tape cassette, the sliding operation being conducted with flexurally deforming the support plate against elasticity of the support plate.
According to this configuration, the spring plate 34 and the spring members 44 in the conventional art are not necessary, and a magnetic tape device can be configured without using those kinds of members.